Technical Abstract:
Abstract: Salmonella enterica subsp. I serovar Enteritidis (S. Enteritidis) is the most frequent cause of salmonellosis in the world. Epidemiological data from the Centers for Disease Control indicates that the incidence of illness from S. Enteritidis in the United States increased during 2005 despite seeing reductions in other food borne pathogens. There is a lack of knowledge about which genetic determinants can be used to detect emerging outbreak potential of this pathogen. To detect small scale genetic determinants linked to phenotype, comparative genomic sequencing using the Sanger Institute PT4 S. Enteritidis database as the reference genome was used to detect single nucleotide polymorphisms (SNPs) that were present between two strains that varied in their ability to contaminate eggs and to grow to high cell density. Virtual subtraction hybridization of two separate SNP databases has putatively located a total of 393 polymorphisms located in 337 genes and 39 non-coding regions (there are some doublets). Confirmatory sequencing is pending. However, three SNPs in rrlC, rrlA and cyaA [GenBank 78214643] that had been previously located and characterized by ribotyping and sequencing were detected by comparative genomic sequencing and confirmed by manual sequencing.